Quartzite is a compact hard metamorphic rock which was originally sandstone. Pure quartzite is a recrystalized sandstone with siliceous cement, often over 99% of SiO2 content and almost exclusively built of quartz grains cemented with silica. In the insulating material industry, that name of fire-proof quartzite is used for both pure quartzite and other silica-rich rocks such as quartzitic sandstones and schists.
Refractory quartzites are used in metallurgy for making ferroalloys and in insulating material industry for making siliceous fire-proof materials.
In Poland, refractory quartzites deposits were documented in two regions: the Lower Silesian region and the Holy Cross Mts (map). In the Lower Silesia, proven deposits occur in the area between Bolesławiec, Lubań and Lwówek Śląski and in the vicinities of Strzelin. They are formed of irregular quartzitic layers and lenses dated at the Neogene. The majority of these sites were exploited in the past so the abandoned deposits still comprise some relict resources. In 2015 the Marshal of the Dolnośląskie Voivodeship decided to cross ten deposits out from “The balance…”: nine of them are abandoned deposits - Barbara, Borowiany, Brzeźnik, Kleszczowa I (Kliczków), Kleszczowa II (Kliczków), Książkowice, Nawojów-Rzeczka, Ołobole I-II and Parzyce and one is covered by the detailed exploration – Milików II. Nowadays, only Milików deposit is covered by the detailed exploration and has not been exploited so far.
Quartzite deposits occurring in the Holy Cross Mts are formed by quartzite intercalations in clays and clay shales of the Paleozoic age. The deposits were explored in the 1950s but only one of them (Bukowa Góra) is still being exploited. The raw material of that deposit has not been classified as refractory quartzite but as quartzitic sandstone. Therefore, Bukowa Góra deposit is discussed in the section on dimension and crushed stones. Nevertheless, the raw material from that deposit is exploited and processed for use in the producing fire-proof quartzite materials.
The table 1 shows resources and the current state of development and exploration of refractory quartzites.
Anticipated economic resources of the refractory quartzites amounted to 6.59 million tonnes in 2015 and decreased by 0.29 million tonnes in comparison with the previous year (table 2).
The figure given below shows resources and production of refractory quartzites in Poland in the years 1989-2015.
Prepared by: Agnieszka Malon